1. Field of the Invention
The present invention relates to an apparatus and a method for correcting image errors in a shuttle type of a scanner, and more particularly to an apparatus and a method for correcting image errors in a shuttle type of a scanner, in which are capable of correcting the image errors due to an alignment tolerance of the scanner and an inertia generated in a shuttle movement.
2. Description of the Prior Art
In a shuttle type of a scanner, a scanning head must be moved in a direction normal (orthogonal or perpendicular) to a direction in which a document is carried. This means that an alignment tolerance is a zero. The shuttle type of the scanner makes the scanning head move left to right or right to left (reciprocating movement of the head) while scanning an image on the document. Image errors can be generated in the scanned image due to a mechanical tolerance of the scanner.
The scanning head is mounted on a guide shaft so as to be guided while the scanning head is reciprocated along the guide shaft. The scanning head, however, inclines (skews) due to an inertia as it reciprocated along the guide shaft. While the document is scanned by the scanner, the scanned data have errors in that the image is inclined (skewed). Therefore, it is necessary to correct the image errors in the image data.
In order to correct the image errors, according to the conventional art, a reference sticker R having a pattern is attached at an end portion of an effective scanning area in the scanner, as shown in FIG. 1, and the scanner scans, band by band, the pattern of the reference sticker R to detect an error between a first datum and a last datum of each band. Then, the scanned image data are corrected according to the detected error.
According to the conventional art, however, when the reference sticker R is attached at the end portion of the scanning area in the scanner in order to correct the image error generated during the scanning, it is impossible to correct an error which is generated during a process of attaching the reference sticker to the scanner. As a result, the error is continuously generated due to the original error in attaching reference sticker.
In order to correct the error due to failing to properly attach the reference sticker to the scanner, a precise apparatus is required to accurately attach the reference sticker to the scanner. Accordingly, the productivity of the scanner can be degraded and the manufacturing cost can be increased. If the reference sticker is contaminated, it is impossible to correct the image errors accurately. In order to prevent the reference sticker from being contaminated, the reference sticker must remain clean by attaching a cover thereby making the process of producing the scanner more complicated.